Apparatus and method for upgrading software of a wireless mobile station

ABSTRACT

A software upgrade server capable of upgrading a wireless mobile station via a wireless network. The software upgrade server comprises: 1) a database for storing a plurality of software upgrade files as a plurality of object files and a plurality of image files suitable for use in the wireless mobile station; and 2) an upgrade controller associated with the database for communicating with the mobile station via the wireless network. The upgrade controller receives from the mobile station a select message selecting one of the software upgrade files and a target address associated with an original image file in a memory of the mobile station. The upgrade controller links selected object files to form a dynamically linked library (DLL) file based on the target address. The upgrade controller retrieves from the database a copy of the original image file and generates a delta file corresponding to differences between the original image file and the DLL file and transmits the delta file to the wireless mobile station.

CROSS-REFREENCE TO RELATED APPLICATION

[0001] This application is a continuation-in-part (CIP) of U.S. patentapplication Ser. No. 10/310,738, filed on Dec. 5, 2002 and entitled“APPARATUS AND METHOD FOR REMOTE DLL LINKING OF SOFTWARE UPGRADES FOR AWIRELESS MOBILE STATION”. The disclosure of related patent applicationSer. No. 10/310,738 is hereby incorporated by reference into the presentdisclosure as if fully set forth herein.

TECHNICAL FIELD OF THE INVENTION

[0002] The present invention is directed generally to wirelesscommunication systems and, more specifically, to an apparatus and methodfor upgrading the software in a wireless mobile station.

BACKGROUND OF THE INVENTION

[0003] In order to increase the wireless market to the greatest extentpossible, wireless service providers and wireless equipmentmanufacturers constantly seek new ways to make wireless equipment andservices as convenient, user-friendly, and affordable as possible. Tothat end, wireless service providers and the manufacturers of cellphones and other wireless mobile stations frequently work together tostreamline procedures for enrolling and equipping new subscribers andfor improving the services and equipment of existing subscribers.

[0004] One important aspect of these efforts involves over-the-air (OTA)provisioning and upgrading of wireless mobile stations, such as cellphones, wireless personal digital assistants (PDAs), wireless hand-heldcomputers, two-way pagers, and the like. OTA provisioning is arelatively new feature that enables a new subscriber who purchases a newcell phone (or other mobile station) to set-up an account with awireless service provider and to configure the phone for operation. TheOTA provisioning procedure is mostly automated and does not require thenew subscriber to visit a cell phone service center. Typically, the newsubscriber removes the new cell phone from its box, calls a specialpurpose telephone number (given in the instructions), and performs aninteractive provisioning procedure with an automated agent or a humanservice representative.

[0005] Over-the-air upgrading of wireless mobile stations also is arelatively new procedure that enables a subscriber to download andinstall upgraded software containing patches, bug fixes, and newerversions of mobile station software, including the operating system. Thewireless service provider or the mobile station manufacturer, or both,may provide the upgraded software.

[0006] It has long been possible to download and to install softwareupgrades for a personal computer (PC) via the Internet. However, thisprocess is considerably more complicated in a mobile station. A personalcomputer has far more resources available to perform a software upgrade,including dynamically linked libraries (DLLs), a memory management unit(MMU), and a large random access memory (RAM) space. A conventional PCsoftware upgrade may be partitioned and downloaded to a personalcomputer as a group of shared objects. If one object file is corruptedor interrupted during transmission, only that object file needs to bere-transmitted. The object files that are properly received do not needto be re-transmitted. Once all object files are present, the memorymanagement unit (MMU) of the PC loads all of the object files into RAMand re-links the object files to form a DLL. The DLL may then be storedback into ROM (i.e., disk) in the PC. During this process, the MMU iscapable of modifying portions of the code or the symbol table.

[0007] However, a wireless mobile station (e.g., a cell phone) typicallyhas far fewer resources available than a PC. Mobile stations lack amemory management unit and code is not executed from RAM. Code isexecuted out of a Flash memory that acts as a read-only memory (ROM).The Flash memory generally cannot be written to, it can only bere-programmed with great difficulty. These resource limitations greatlycomplicate software upgrade operations in wireless mobile stations.

[0008] Therefore, there is a need in the art for improved systems andmethods for performing automatic software upgrades of wireless handsetsand other types of mobile stations. In particular, there is a need inthe art for systems and methods for performing over-the-air softwareupgrades that permit the use of methods similar to dynamic linkinglibraries (DLLs) in the mobile station handset.

SUMMARY OF THE INVENTION

[0009] To address the above-discussed deficiencies of the prior art, itis a primary object of the present invention to provide a mobile stationcapable of being upgraded by a delta file received from a softwareupgrade server via a wireless network. According to an advantageousembodiment of the present invention, the mobile station comprises: 1) amemory capable of storing an original image file and the delta file,wherein the delta file is suitable for upgrading the original imagefile; and 2) a controller associated with the memory capable ofcommunicating with the software upgrade server via the wireless network.The controller receives at least a first message from the softwareupgrade server identifying an upgraded image file corresponding to theoriginal image file. The controller, in response to the first message,transmits to the software upgrade server a target address in the memoryassociated with the original image file. The controller is furthercapable of modifying the original image file according to instructionsstored in the delta file to thereby generate the upgraded image file inthe memory.

[0010] It is another primary object of the present invention to providea software upgrade server capable of upgrading a wireless mobile stationvia a wireless network. According to an advantageous embodiment of thepresent invention, the software upgrade server comprises: 1) a databasecapable of storing a plurality of software upgrade files as a pluralityof object files and a plurality of image files suitable for use in thewireless mobile station; and 2) an upgrade controller associated withthe database capable of communicating with the mobile station via thewireless network. The upgrade controller receives from the mobilestation a select message selecting one of the plurality of softwareupgrade files and a target address associated with an original imagefile in a memory of the mobile station. The upgrade controller, inresponse to receipt of the target address, links selected ones of theplurality of object files to form a dynamically linked library (DLL)file based on the target address. The upgrade controller retrieves fromthe database a copy of the original image file and generates a deltafile corresponding to differences between the original image file andthe DLL file and transmits the delta file to the wireless mobilestation.

[0011] The foregoing has outlined rather broadly the features andtechnical advantages of the present invention so that those skilled inthe art may better understand the detailed description of the inventionthat follows. Additional features and advantages of the invention willbe described hereinafter that form the subject of the claims of theinvention. Those skilled in the art should appreciate that they mayreadily use the conception and the specific embodiment disclosed as abasis for modifying or designing other structures for carrying out thesame purposes of the present invention. Those skilled in the art shouldalso realize that such equivalent constructions do not depart from thespirit and scope of the invention in its broadest form.

[0012] Before undertaking the DETAILED DESCRIPTION OF THE INVENTIONbelow, it may be advantageous to set forth definitions of certain wordsand phrases used throughout this patent document: the terms “include”and “comprise,” as well as derivatives thereof, mean inclusion withoutlimitation; the term “or,” is inclusive, meaning and/or; the phrases“associated with” and “associated therewith,” as well as derivativesthereof, may mean to include, be included within, interconnect with,contain, be contained within, connect to or with, couple to or with, becommunicable with, cooperate with, interleave, juxtapose, be proximateto, be bound to or with, have, have a property of, or the like; and theterm “controller” means any device, system or part thereof that controlsat least one operation, such a device may be implemented in hardware,firmware or software, or some combination of at least two of the same.It should be noted that the functionality associated with any particularcontroller may be centralized or distributed, whether locally orremotely. Definitions for certain words and phrases are providedthroughout this patent document, those of ordinary skill in the artshould understand that in many, if not most instances, such definitionsapply to prior, as well as future uses of such defined words andphrases.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] For a more complete understanding of the present invention, andthe advantages thereof, reference is now made to the followingdescriptions taken in conjunction with the accompanying drawings,wherein like numbers designate like objects, and in which:

[0014]FIG. 1 illustrates an exemplary wireless network according to oneembodiment of the present invention;

[0015]FIG. 2 illustrates an exemplary mobile station in greater detailaccording to one embodiment of the present invention;

[0016]FIG. 3 illustrates an exemplary upgrade server according to oneembodiment of the present invention;

[0017]FIG. 4 is a flow diagram illustrating an upgrade operation of amobile station according to a first exemplary embodiment of the presentinvention; and

[0018]FIG. 5 is a flow diagram illustrating an upgrade operation of amobile station according to a second exemplary embodiment of the presentinvention.

DETAILED DESCRIPTION OF THE INVENTION

[0019]FIGS. 1 through 5, discussed below, and the various embodimentsused to describe the principles of the present invention in this patentdocument are by way of illustration only and should not be construed inany way to limit the scope of the invention. Those skilled in the artwill understand that the principles of the present invention may beimplemented in any suitably arranged wireless network.

[0020]FIG. 1 illustrates exemplary wireless network 100 according to oneembodiment of the present invention. Wireless network 100 comprises aplurality of cell sites 121-123, each containing one of the basestations, BS 101, BS 102, or BS 103. Base stations 101-103 communicatewith a plurality of mobile stations (MS) 111-114 over code divisionmultiple access (CDMA) channels. Mobile stations 111-114 may be anysuitable wireless devices, including conventional cellularradiotelephones, PCS handset devices, personal digital assistants,portable computers, or metering devices. The present invention is notlimited to mobile devices. Other types of access terminals, includingfixed wireless terminals, may be used. However, for the sake ofsimplicity, only mobile stations are shown and discussed hereafter.

[0021] Dotted lines show the approximate boundaries of the cell sites121-123 in which base stations 101-103 are located. The cell sites areshown approximately circular for the purposes of illustration andexplanation only. It should be clearly understood that the cell sitesmay have other irregular shapes, depending on the cell configurationselected and natural and man-made obstructions.

[0022] As is well known in the art, cell sites 121-123 are comprised ofa plurality of sectors (not shown), each sector being illuminated by adirectional antenna coupled to the base station. The embodiment of FIG.1 illustrates the base station in the center of the cell. Alternateembodiments position the directional antennas in corners of the sectors.The system of the present invention is not limited to any particularcell site configuration.

[0023] In one embodiment of the present invention, BS 101, BS 102, andBS 103 comprise a base station controller (BSC) and one or more basetransceiver subsystem(s) (BTS). Base station controllers and basetransceiver subsystems are well known to those skilled in the art. Abase station controller is a device that manages wireless communicationsresources, including the base transceiver stations, for specified cellswithin a wireless communications network. A base transceiver subsystemcomprises the RF transceivers, antennas, and other electrical equipmentlocated in each cell site. This equipment may include air conditioningunits, heating units, electrical power supplies, telephone lineinterfaces, and RF transmitters and RF receivers. For the purpose ofsimplicity and clarity in explaining the operation of the presentinvention, the base transceiver subsystem in each of cells 121, 122, and123 and the base station controller associated with each basetransceiver subsystem are collectively represented by BS 101, BS 102 andBS 103, respectively.

[0024] BS 101, BS 102 and BS 103 transfer voice and data signals betweeneach other and the public switched telephone network (PSTN) (not shown)via communication line 131 and mobile switching center MSC) 140. BS 101,BS 102 and BS 103 also transfer data signals, such as packet data, withthe Internet (not shown) via communication line 131 and packet dataserver node (PDSN) 150. Line 131 also provides the connection path totransfers control signals between MSC 140 and BS 101, BS 102 and BS 103used to establish connections for voice and data circuits between MSC140 and BS 101, BS 102 and BS 103.

[0025] Communication line 131 may be any suitable connection means,including a T1 line, a T3 line, a fiber optic link, a network packetdata backbone connection, or any other type of data connection. Line 131links each vocoder in the BSC with switch elements in MSC 140. Thoseskilled in the art will recognize that the connections on line 131 mayprovide a transmission path for transmission of analog voice bandsignals, a digital path for transmission of voice signals in the pulsecode modulated (PCM) format, a digital path for transmission of voicesignals in an Internet Protocol (IP) format, a digital path fortransmission of voice signals in an asynchronous transfer mode (ATM)format, or other suitable connection transmission protocol. Thoseskilled in the art will recognize that the connections on line 131 mayprovide a transmission path for transmission of analog or digitalcontrol signals in a suitable signaling protocol.

[0026] MSC 140 is a switching device that provides services andcoordination between the subscribers in a wireless network and externalnetworks, such as the PSTN or Internet. MSC 140 is well known to thoseskilled in the art. In some embodiments of the present invention,communications line 131 may be several different data links where eachdata link couples one of BS 101, BS 102, or BS 103 to MSC 140.

[0027] In the exemplary wireless network 100, MS 111 is located in cellsite 121 and is in communication with BS 101. MS 113 is located in cellsite 122 and is in communication with BS 102. MS 114 is located in cellsite 123 and is in communication with BS 103. MS 112 is also locatedclose to the edge of cell site 123 and is moving in the direction ofcell site 123, as indicated by the direction arrow proximate MS 112. Atsome point, as MS 112 moves into cell site 123 and out of cell site 121,a hand-off will occur.

[0028] As is well known, the hand-off procedure transfers control of acall from a first cell site to a second cell site. As MS 112 moves fromcell 121 to cell 123, MS 112 detects the pilot signal from BS 103 andsends a Pilot Strength Measurement Message to BS 101. When the strengthof the pilot transmitted by BS 103 and received and reported by MS 112exceeds a threshold, BS 101 initiates a soft hand-off process bysignaling the target BS 103 that a handoff is required as described inTIA/EIA IS-95 or TIA/EIA IS-2000.

[0029] BS 103 and MS 112 proceed to negotiate establishment of acommunications link in the CDMA channel. Following establishment of thecommunications link between BS 103 and MS 112, MS 112 communicates withboth BS 101 and BS 103 in a soft handoff mode. Those acquainted with theart will recognize that soft hand-off improves the performance on bothforward (BS to MS) channel and reverse (MS to BS) channel links. Whenthe signal from BS 101 falls below a predetermined signal strengththreshold, MS 112 may then drop the link with BS 101 and only receivesignals from BS 103. The call is thereby seamlessly transferred from BS101 to BS 103. The above-described soft hand-off assumes the mobilestation is in a voice or data call. An idle hand-off is the hand-offbetween cells sites of a mobile station that is communicating in thecontrol or paging channel.

[0030] Any or all of the mobile stations in wireless network 100 may beupgraded by means of an over-the-air (OTA) upgrade procedure thattransfers new software to the mobile stations from remote upgrade server300 shown in FIG. 3. According to the principles of the presentinvention, upgrade server 300 provides a selected mobile station, forexample MS 111, with the resources that are available to a personalcomputer, but normally lacking in a cell phone or similar mobilestation. In particular, upgrade server 300 receives a target address inmemory from a mobile station (e.g., MS 111) and, in response, uses thetarget address to remotely link a group of shared objects associatedwith a particular software upgrade to form a dynamically linked library(DLL). The DLL file is then transmitted over the air for the mobilestation and is loaded into memory at the target address. In this manner,the intense processing associated with re-linking a DLL is performedremotely rather than in the mobile station.

[0031] According to an advantageous embodiment of the present invention,the initial upgrade of a mobile station (e.g., MS 111) and subsequentsmaller upgrades may be performed by means of a delta file. In such anembodiment, upgrade server 300 transmits a delta file (d_(xy)) to themobile station. The mobile station executes a software algorithm thatreads instructions- and data from the delta file. The software algorithmmodifies, for example, the existing operating system software to producea new (or upgraded) version of the operating system software. In thisadvantageous embodiment, the present invention downloads a small deltafile over the air to the mobile station, rather than a large image file,thereby conserving network bandwidth.

[0032] The generation of a delta file involves two tasks: 1) a utilityapplication generates the smallest possible binary difference (“deltafile”) between two versions of mobile station executable firmware; and2) a software algorithm running on the mobile station receives thebinary delta file as input and applies it to the existing image file onthe mobile station to transform the existing image file into a new imagefile.

[0033] For example, let I_(o) be the old image (e.g., revision 1.0) andlet I_(N) be the new image (e.g., revision 1.1). T(x,y) is the utilityapplication that takes two images x and y and produces a delta file,d_(xy). P(d_(xy), x) is the software algorithm that takes the delta,d_(xy), and an image x, and reconstructs the new image file y. The newimage file y is a bit exact copy of the original image file y used byT(x,y).

[0034] The present invention comprises the following steps:

[0035] 1) Compute d_(xy)=T (I_(O), I_(N)) on a host workstation orserver;

[0036] 2) Send d_(xy) over the air to the mobile station. For typicalcases, the size of d_(xy) is much smaller than size of I_(N).

[0037] 3) Execute the software algorithm P(d_(xy), I_(o)) on the phone.The output of P(d_(xy), I_(o)) is the bit exact representation of imageI_(N).

[0038]FIG. 2 illustrates wireless mobile station 111 according to anadvantageous embodiment of the present invention. Wireless mobilestation 111 comprises antenna 205, radio frequency (RF) transceiver 210,transmit (TX) processing circuitry 215, microphone 220, and receive (RX)processing circuitry 225. MS 111 also comprises speaker 230, mainprocessor 240, input/output (I/O) interface (IF) 245, keypad 250,display 255, and memory 260. Memory 260 further comprises basicoperating system (OS) program 261, upgrade control program 262,re-linked DLL space 263, P(d_(xy), I_(O)) algorithm program 264, anddelta (d_(xy)) file 265. Re-linked DLL space 263 begins at targetaddress 270. A DLL received in an over-the-air (OTA) upgrade procedureis stored in memory 260 beginning at target address 270.

[0039] Radio frequency (RF) transceiver 210 receives from antenna 205 anincoming RF signal transmitted by a base station of wireless network100. Radio frequency (RF) transceiver 210 down-converts the incoming RFsignal to produce an intermediate frequency (IF) or a baseband signal.The IF or baseband signal is sent to receiver (RX) processing circuitry225 that produces a processed baseband signal by filtering, decoding,and/or digitizing the baseband or IF signal to produce a processedbaseband signal. Receiver (RX) processing circuitry 225 transmits theprocessed baseband signal to speaker 230 (i.e., voice data) or to mainprocessor 240 for further processing (e.g., web browsing).

[0040] Transmitter (TX) processing circuitry 215 receives analog ordigital voice data from microphone 220 or other outgoing baseband data(e.g., web data, e-mail, interactive video game data) from mainprocessor 240. Transmitter (TX) processing circuitry 215 encodes,multiplexes, and/or digitizes the outgoing baseband data to produce aprocessed baseband or IF signal. Radio frequency (RF) transceiver 210receives the outgoing processed baseband or IF signal from transmitter(TX) processing circuitry 215. Radio frequency (RF) transceiver 210up-converts the baseband or IF signal to a radio frequency (RF) signalthat is transmitted via antenna 205.

[0041] In an advantageous embodiment of the present invention, mainprocessor 240 is a microprocessor or microcontroller. Memory 260 iscoupled to main processor 240. According to an advantageous embodimentof the present invention, part of memory 260 comprises a random accessmemory (RAM) and another part of memory 260 comprises a Flash memory,which acts as a read-only memory (ROM).

[0042] Main processor 240 executes basic operating system (OS) program261 stored in memory 260 in order to control the overall operation ofwireless mobile station 111. In one such operation, main processor 240controls the reception of forward channel signals and the transmissionof reverse channel signals by radio frequency (RF) transceiver 210,receiver (RX) processing circuitry 225, and transmitter (TX) processingcircuitry 215, in accordance with well-known principles.

[0043] Main processor 240 is capable of executing other processes andprograms resident in memory 260. Main processor 240 can move data intoor out of memory 260, as required by an executing process. Mainprocessor 240 is also coupled to I/O interface 245. I/O interface 245provides mobile station 111 with the ability to connect to other devicessuch as laptop computers and handheld computers. I/O interface 245 isthe communication path between these accessories and main controller240.

[0044] Main processor 240 is also coupled to keypad 250 and display unit255. The operator of mobile station 111 uses keypad 250 to enter datainto mobile station 111. Display 255 may be a liquid crystal displaycapable of rendering text and/or at least limited graphics from websites. Alternate embodiments may use other types of displays.

[0045] In accordance with the principles of the present invention, mainprocessor 240 is capable of receiving and installing software upgradesunder the control of upgrade control program 262. This over-the-air(OTA) upgrade may be performed in one of two ways. In a first OTAprocedure, if the upgraded program is entirely new to MS 111, or isradically different than a previous version, the entire upgraded programmay be remotely linked in upgrade server 300 and then transmitted in itsentirety to MS 111. Alternatively, in a second OTA procedure, if theupgraded program differs from an existing program already installed inMS 111 by a relatively small amount, delta files may be used.

[0046] In this second procedure, the upgraded program is remotely linkedin upgrade server 300, and a difference detection program is used todetermine the differences between the upgraded program and the previousversion of that program that is already installed in MS 111. Upgradeserver 300 then generates one or more delta files based on the detecteddifferences between the two programs. Finally, only the one or moredelta files are transmitted to MS 111.

[0047] The above-described OTA upgrade procedures may be initiated inany conventional triggering event, such an operator-initiated action, anautomated periodic procedure (i.e., expiration or a timer in MS 111), orreceipt of a notification message from upgrade server 300. Thenotification message may include a Short Messaging Service (SMS)-basedOTA notification. In response to any of these triggering events, mainprocessor 240 establishes a communication link to wireless network 100and to server 300 via the Internet connection of wireless network 100.

[0048] When the communication link is established, main processor 240requests a list of available upgrades for a mobile station of its type.Upgrade server 300 responds with a list of upgrade programs and theresource needs (i.e., memory space, processor speed) of those upgradeprograms. Alternatively, when the communication link is established,upgrade server 300 may simply tell main processor 240 that a softwareupgrade file is available and ready to be transmitted.

[0049] Main processor 240 then selects a desired upgrade program (withoperator approval, if necessary) and determines a contiguous space inmemory 260 that is large enough to hold the selected upgrade program. InFIG. 2, this space is re-linked DLL space 263, which begins at targetaddress 270. Main processor 240 notifies upgrade server 300 (shown inFIG. 3) of the identity of the selected upgrade program and alsonotifies upgrade server 300 that the DLL is to be stored at targetaddress 270.

[0050]FIG. 3 illustrates exemplary upgrade server 300 according to oneembodiment of the present invention. Upgrade server 300 comprisesupgrade controller 305 and memory 310. Memory 310 stores applicationprograms and data associated with the operation of upgrade server 300,including upgrade server application program 315, dynamic linkinglibrary (DLL) re-linking application program 320, T(x,y) utilityalgorithm program 325, and mobile station (MS) upgrade database 330. MSupgrade database 330 comprises a plurality of object files, includingexemplary object files 331, 332, and 333, and a plurality of image filesassociated with mobile station 111, including exemplary image files 341,342, and 343. As will be explained below in greater detail, T(x,y)utility algorithm program 325 and image files 341, 342 and 343 are usedin connection with the generation of delta files that are capable ofupgrading MS 111.

[0051] Upgrade controller 305 operates under the control of upgradeserver application program 315 to provide software upgrade services formobile stations in wireless network 100. Upgrade server applicationprogram 315 communicates with main processor 240 in MS 111. Upgradeserver application program 315 receives requests for upgrades from MS111 and identifies in MS upgrade database 330 available upgradesaccording to the vendor and model of MS 111, or some similar criteria.Upgrade server application program 315 also receives target address 270from MS 111 and, in response, launches DLL re-linking program 320. DLLre-linking program 320 identifies selected ones of the object files inMS upgrade database that are associated with the software upgraderequested by MS 111. DLL re-linking program 320 then uses target address270 to re-link the identified object files into a DLL file. If the DLLfile for an entirely new program (i.e., not already resident in MS 111),then the DLL file is transferred to upgrade controller 305, which relaysthe DLL file to MS 111 for an OTA download.

[0052]FIG. 4 depicts flow diagram 400, which illustrates an upgradeoperation of MS 111 according to an exemplary embodiment of the presentinvention. In response to one or more of: 1) a user prompt; 2) a timerexpiration; or 3) a notification message from upgrade server 300, MS 111requests and receives from upgrade server 300 information regardingavailable software upgrades. In response, MS 111 identifies a suitablecontiguous block of memory 260 (i.e., flash memory) for saving there-linked DLL code (process step 405).

[0053] MS 111 then transmits target address 270 to upgrade server 300(process step 410). Upgrade server 300 retrieves the required objectfiles for the requested upgrade software and re-links the object filesto form a DLL based on target address 270 (process step 415). Next, there-linked DLL is transmitted to MS 111 (process step 420). MS 111re-programs the flash memory and stores the re-linked DLL file in memory260 beginning at target address 270 (process step 425). On reboot, MS111 is pointed to target address 270 to execute the re-linked DLL code(process step 430).

[0054] In the foregoing description, it is assumed that the targetaddress is the starting point of the available memory space in memory260. This is not strictly necessary, however. Those of ordinary skill inthe art will recognize that upgrade server 300 and MS 111 may readily bemodified to operate with a target address located at the end, or at anintermediate point in the available memory space. In such alternateembodiments, upgrade server 300 can use the end point (or intermediatepoint) and the file size to calculate the starting point in memory 260where the DLL must be located. Upgrade server 300 then uses thecalculated starting point to link the DLL file.

[0055] As noted above, if the upgraded program differs from an existingprogram installed in MS 111 by a relatively small amount, delta filesmay be used. According to the principles of the present invention,upgraded software is sent to mobile station 111 in the form of delta(d_(xy)) file 265 that is stored in memory 265. Next, P(d_(xy), I_(O))algorithm program 264 takes delta file 265 as its input and applies itto an original image file, I_(O), that is already installed on MS 111 toproduce a new image file, I_(N). For example, the I_(O) image file to beupgraded may be the application program residing in re-linked DLL space263, beginning at target address 270. An upgrade is accomplished byexecuting P(d_(xy), I_(O)) algorithm program 264 from Flash memory andmodifying the application program residing in re-linked DLL space 263according to data and instructions in delta (d_(xy)) file 265 to producean upgraded image file, I_(N). Thereafter, MS 111 executes the upgradedversion of the application program residing in re-linked DLL space 263.

[0056] The generation of delta files, such as delta file 265, isaccomplished in upgrade server 300 by comparing the differences betweenthe upgraded program, such as the remotely linked DLL file, and theprevious version of the same program that is known to reside in MS 111.Upgrade server application program 315 receives requests for upgradesfrom MS 111 and/or informs MS 111 that an upgrade is available. Upgradeserver application program 315 identifies available upgrades in MSupgrade database 330 according to the vendor and model of MS 111, orsome similar criteria.

[0057] Upgrade server application program 315 also receives the currentversion number of a software application on MS 111. Upgrade serverapplication program 315 uses the current version number to identify anoriginal (or current) image file (I_(O)) that is already installed in MS111 and a new (or upgraded) image file (I_(N)) in MS upgrade database330. According to the principles of the present invention, the originalimage file (I_(O)) may comprise a DLL file that was previously linked inupgrade server 300 and transmitted to MS 111. Additionally, the new (orupgraded) image file (I_(N)) may be formed by linking two or more objectfiles 331-333 as described above in FIG. 4. In this regard, MS 111 maytransmit target address 270 of the original image file (I_(O)) inre-linked DLL space 263. Upgrade server 300 may then use target address270 to identify the corresponding original image file (I_(O)) stored inMS upgrade database 330.

[0058] Upgrade server application program 315 then executes T(x,y)utility algorithm program 325 on I_(O) and I_(N) to produce delta file(d_(xy)) file 265 for transmission to MS 111. Since target address 270is the same for I_(O) and I_(N), upgrade server application program 315uses target address 270 to generate delta file 265. Delta file 265 istransferred to upgrade controller 305, which relays delta file 265 to MS111 for an OTA download.

[0059]FIG. 5 depicts flow diagram 500, which illustrates an upgradeoperation of mobile station 111 via wireless network 100 according to anexemplary embodiment of the present invention. In response to one ormore of: 1) a user prompt; 2) a timer expiration; or 3) a notificationmessage from upgrade server 300, MS 111 transmits to upgrade server 300information regarding the version number of existing software programsin MS 111 (process step 505). This information includes target address270 for each such software program. Upgrade server 300 uses the versioninformation and target address 270 to search MS upgrade database 330 andfetch the original image file, I_(O). Upgrade server 300 also searchesfor a new (or upgrade) image file, I_(N), corresponding to the originalimage file, I_(O), for that particular type of mobile station (processstep 510).

[0060] Next, upgrade server 300 executes T(x,y) utility algorithmprogram 325 with x=I_(O) and y=I_(N) as inputs. The output is delta(d_(xy)) file 265 (process step 515) Optionally, in situations in whichMS 111 does not already contain P(d_(xy), I_(O)) algorithm program 264,upgrade server 300 may add P(d_(xy), I_(O)) algorithm program 264 todelta file 265 in order to carry out the upgrade. Delta file 265 is thentransmitted to MS 111 (process step 520). MS 111 receives delta file 265and stores it in temporary non-volatile memory (i.e, Flash memory).Since the size of delta file 265 generally is very small compared to thesize of either the I_(O) image file or the I_(N) image file, this doesnot present a memory problem.

[0061] After the entire delta (d_(xy)) file 265 is downloaded, MS 111verifies delta (d_(xy)) file 265 for integrity, using MD5, HMAC-MD5, orsome similar check-sum algorithm. Subsequently, MS 111 executesP(d_(xy), I_(O)) algorithm program 264. The original image file, I_(O),is already present on MS 111. Execution of P(d_(xy), I_(O)) algorithmprogram 264 transforms the original image file, I_(O) (i.e., operatingsystem program 261), into an exact copy of the new image, I_(N) (processstep 525). After reboot, MS 111 executes the new (or upgraded) imagefile (process step 530).

[0062] According to an exemplary embodiment of the present invention,delta (d_(xy)) file 265 may contain the following essential information:

[0063] 1) A cryptographic secure checksum of the new image I_(N), whichis verified after P(d_(xy), I_(O)) algorithm program 264 completes itsoperation;

[0064] 2) The final size of I_(N); and

[0065] 3) Instructions to transform the old image file, I_(O), into thenew image file, I_(N).

[0066] The instructions in delta (d_(xy)) file 265 may be, for example:

[0067] a) Add M bytes of literal data at offset N;

[0068] b) Copy data from original image at offset M to new offset N;and/or

[0069] c) Delete N bytes of data at offset M.

[0070] Optionally, delta (d_(xy)) file 265 may be compressed to furtherreduce the OTA transfer size using any of a number of conventionalalgorithms, including LZW, GZIP, BZIP2, RLE, ZIP, and the like.

[0071] Alternatively, delta (d_(xy)) file 265 may be downloaded to apersonal computer (PC) via the internet and MS 111 may be re-programmedvia the serial port and special customer support software running on thePC. This alternative allows mass updates of software quickly and easily,since the entire software need not be programmed—only a small deltafile.

[0072] Although the present invention has been described in detail,those skilled in the art should understand that they can make variouschanges, substitutions and alterations herein without departing from thespirit and scope of the invention in its broadest form.

What is claimed is:
 1. A mobile station capable of being upgraded by adelta file received from a software upgrade server via a wirelessnetwork, said mobile station comprising: a memory capable of storing anoriginal image file and said delta file, wherein said delta file issuitable for upgrading said original image file; and a controllerassociated with said memory capable of communicating with said softwareupgrade server via said wireless network, wherein said controllerreceives at least a first message from said software upgrade serveridentifying an upgraded image file corresponding to said original imagefile and said controller, in response to said first message, transmitsto said software upgrade server a target address in said memoryassociated with said original image file, and wherein said controller isfurther capable of modifying said original image file according toinstructions stored in said delta file to thereby generate said upgradedimage file in said memory.
 2. The mobile station as set forth in claim 1wherein said target address indicates a starting point of said originalimage file in said memory.
 3. The mobile station as set forth in claim 1wherein said controller is capable of communicating with said softwareupgrade server via said wireless network, wherein said controllertransmits to said software upgrade server a version indicia identifyinga current version of said original image file.
 4. The mobile station asset forth in claim 3 wherein said controller transmits said versionindicia to said software upgrade server in response to a notificationmessage received from said upgrade server.
 5. The mobile station as setforth in claim 3 wherein said controller transmits said version indiciato said software upgrade server in response to a user prompt receivedfrom an operator of said mobile station.
 6. The mobile station as setforth in claim 3 wherein said controller transmits said version indiciato said software upgrade server in response to expiration of a timer. 7.The mobile station as set forth in claim 7 wherein said delta filecomprises a file size associated with said new image file.
 8. The mobilestation as set forth in claim 6 wherein said delta file comprises atleast one checksum value associated with said new image file.
 9. Themobile station as set forth in claim 1 wherein said controllerdetermines from said at least a first message received from saidsoftware upgrade server a file size of said upgraded image file.
 10. Themobile station as set forth in claim 1 wherein said controller iscapable of transmitting an upgrade request message to said softwareupgrade server requesting a list of available software files capable ofbeing executed by said mobile station.
 11. For use in a mobile stationcapable of being upgraded by a delta file received from a softwareupgrade server via a wireless network, a method of upgrading an originalimage file stored in a memory of the mobile station comprising the stepsof: receiving at least a first message from the software upgrade serveridentifying an upgraded image file corresponding to the original imagefile; transmitting to the software upgrade server a target address inthe memory associated with the original image file; receiving from thesoftware upgrade server a delta file capable of upgrading the originalimage file stored in the memory of the mobile station; storing the deltafile in the memory of the mobile station; and modifying the originalimage file according to instructions stored in the delta file to therebygenerate the upgraded image file in the memory of the mobile station.12. The method as set forth in claim 11 wherein the target addressindicates a starting point of the original image file in the memory. 13.The method as set forth in claim 11 further comprising the step oftransmitting to the software upgrade server a version indiciaidentifying a current version of the original image file.
 14. The methodas set forth in claim 13 wherein the step of transmitting the versionindicia to the software upgrade server is done in response to anotification message received from the upgrade server.
 15. The method asset forth in claim 13 wherein the step of transmitting the versionindicia to the software upgrade server is done in response to a userprompt received from an operator of the mobile station.
 16. The methodas set forth in claim 13 wherein the step of transmitting the versionindicia to the software upgrade server is done in response to expirationof a timer.
 17. The method as set forth in claim 13 wherein the deltafile comprises a file size associated with the upgraded image file. 18.The method as set forth in claim 17 wherein the delta file comprises atleast one checksum value associated with the upgraded image file. 19.The method as set forth in claim 11 further comprising the step oftransmitting an upgrade request message to the software upgrade serverrequesting a list of available software files capable of being executedby the mobile station.
 20. A software upgrade server capable ofupgrading a wireless mobile station via a wireless network, saidsoftware upgrade server comprising: a database capable of storing aplurality of software upgrade files as a plurality of object files and aplurality of image files suitable for use in said wireless mobilestation; and an upgrade controller associated with said database capableof communicating with said mobile station via said wireless network,wherein said upgrade controller receives from said mobile station aselect message selecting one of said plurality of software upgrade filesand a target address associated with an original image file in a memoryof said mobile station and said upgrade controller, in response toreceipt of said target address, links selected ones of said plurality ofobject files to form a dynamically linked library (DLL) file based onsaid target address, and wherein said upgrade controller retrieves fromsaid database a copy of said original image file and generates a deltafile corresponding to differences between said original image file andsaid DLL file and transmits said delta file to said wireless mobilestation.
 21. The software upgrade server as set forth in claim 20wherein said target address indicates a starting point of said originalimage file in said mobile station memory.
 22. The software upgradeserver as set forth in claim 20 wherein said upgrade controller iscapable of transmitting to said wireless mobile station a notificationmessage operable to cause said wireless mobile station to transmit saidversion indicia to said software upgrade server.
 23. The softwareupgrade server as set forth in claim 20 wherein said upgrade controlleris capable of receiving an upgrade request message from said mobilestation requesting a list of ones of said plurality of software upgradefiles capable of being executed by said mobile station.
 24. For use in asoftware upgrade server, a method of upgrading a wireless mobile stationvia a wireless network comprising the steps of: storing in a database aplurality of software upgrade files as a plurality of object files andstoring in the database a plurality of image files suitable for use inthe wireless mobile station; and receiving from the mobile station aselect message selecting one of the plurality of software upgrade filesand a target address associated with an original image file in a memoryof the mobile station; in response to receipt of the target address,linking selected ones of the plurality of object files to form adynamically linked library (DLL) file based on the target address;retrieving from the database a copy of the original image file;generating a delta file corresponding to differences between theoriginal image file and the DLL file; and transmitting the delta file tothe wireless mobile station via the wireless network.